We have a Joint Account with Vickers and so far can't transfer any USD cash (out) from Vickers to our DBS bank account. Any advice?

The helpline mailed us that on-line instructions (supposedly on Account Management screen) are not visible and don't work for joint accounts!
Being in Europe, and in need of this cash, we just don't know what to do, as the phone line never answers. Does anybody with a joint account have the same problem to withdraw, convert or transfer foreign cash out of Vickers? Thank you for any suggestion (apart from flying to Singapore...)